134 STUDIES IN ANIMAL LIFE. 



these is little more than separated organs of the 

 great insect organism, as the heart, stomach, and 

 brain are united organs of the human organism. 

 Eemove one of these insects from the community, 

 and it will soon perish, for its life is bound up with 

 the whole. 



And so it is every where ; the dependence is uni- 

 versal : 



" Nothing in this world is single, 



All things, by a law divine, 

 In one another's being mingle." 



We are dependent on the air, the earth, the sun- 

 light, the flowers, the plants, the animals, and all 

 created things, directly or indirectly. Nor is the 

 moral dependence less than the physical. "We can 

 not isolate ourselves if we would. The thoughts 

 of others, the sympathies of others, the needs of 

 others these too make up our life ; without these 

 we should quickly perish. 



It was a dream of the youth Cuvier that a His- 

 tory of Nature might be written which would sys- 

 tematically display this universal interdependence. 

 I know few parts of biography so interesting as 

 those which show us great men in their early aspir- 

 ings, when dreams of achievements vaster than 

 the world has seen fill their souls with energy to 

 achieve the something they do afterward achieve. 

 It is, unhappily, too often but the ambition of youth 

 we have to contemplate; and yet the knowledge 

 that after-life brought with it less of hope, less of 



